Grayson is a home rule-class city in and the county seat of Carter County, Kentucky, United States, on US Route 60 and Interstate 64 in the state's northeastern region. It is approx. 21 miles west of Ashland. Within the city limits, the population was 4,217 at the 2010 census. Along with Carter County, the city is closely associated with the nearby Huntington-Ashland, WV-KY-OH Metropolitan Statistical Area and is often erroneously included in..in the MSA being just 9 miles west of the M.S.A's western boundary. The city has grown in size substantially since the opening of Interstate 64 in 1975 throh t Carter County. Immediately afterwards, Grayson experienced several years of commercial sector growtmainly h to serve the Interstate 64 traffic. Since 1990, the city has also seen significant growth in the residential sector with the Interstate making for a faster trip to and from Ashland.